Farah played college tennis at the University of Southern California from 2006 to 2010. He finished his senior season as the number one ranked player in singles, while additionally ranked second in doubles. He won the 2008 NCAA men's doubles national championship, partnering with Kaes Van’t Hof. He occasionally played doubles with future ATP pro Steve Johnson.[4]

Farah's consistent doubles partnership with fellow countryman Juan Sebastián Cabal began at Wimbledon 2011, when they defeated the pair consisting of Pakistani Aisam Qureshi (8 in doubles) and Indian Rohan Bopanna (9 in the world), who were ranked number 5 in the world, 2–6, 6–2 and 21–19, and lost in second round against American Michael Russell and Kazakhstani Mikhail Kukushkin, 6–4, 6–2, 6–3.

In the 2013 Australian Open, Farah and Cabal made their first appearance in the quarterfinals.

In 2017, Farah and Cabal reached their first men's doubles grand slam semifinal at the French Open. In the same tournament he reached the final of the mixed doubles partnering Gronefeld where they lost to Rohan Bopanna and Gabriela Dabrowski in 3 sets.

In July 2018, Farah was given a suspended three month suspension and fined £3,800 for promoting a gambling website on his twitter. Farah would only serve the suspension if there were further breaches of the Tennis Anti-Corruption Program.[5]